Scale-down was calling failoverService.onInstanceStreamDropped synchronously
and waiting for it to complete. Failover retries for up to 30s waiting for
healthy instances, which blocks the Quarkus event loop thread.
This caused:
- Event loop blocked for 15+ seconds
- Redis health checks timing out (also on event loop)
- Scale-down operations failing
Fix: Trigger drain asynchronously without waiting. Scale-down proceeds
immediately while drain happens in background.
Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
Janis
1d121c727c